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Diffstat (limited to 'contrib/llvm/lib/MC/MCSectionMachO.cpp')
| -rw-r--r-- | contrib/llvm/lib/MC/MCSectionMachO.cpp | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/MCSectionMachO.cpp b/contrib/llvm/lib/MC/MCSectionMachO.cpp new file mode 100644 index 0000000..c9f1591 --- /dev/null +++ b/contrib/llvm/lib/MC/MCSectionMachO.cpp @@ -0,0 +1,272 @@ +//===- lib/MC/MCSectionMachO.cpp - MachO Code Section Representation ------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/MC/MCSectionMachO.h" +#include "llvm/MC/MCContext.h" +#include "llvm/Support/raw_ostream.h" +#include <cctype> +using namespace llvm; + +/// SectionTypeDescriptors - These are strings that describe the various section +/// types. This *must* be kept in order with and stay synchronized with the +/// section type list. +static const struct { + const char *AssemblerName, *EnumName; +} SectionTypeDescriptors[MachO::LAST_KNOWN_SECTION_TYPE+1] = { + { "regular", "S_REGULAR" }, // 0x00 + { nullptr, "S_ZEROFILL" }, // 0x01 + { "cstring_literals", "S_CSTRING_LITERALS" }, // 0x02 + { "4byte_literals", "S_4BYTE_LITERALS" }, // 0x03 + { "8byte_literals", "S_8BYTE_LITERALS" }, // 0x04 + { "literal_pointers", "S_LITERAL_POINTERS" }, // 0x05 + { "non_lazy_symbol_pointers", "S_NON_LAZY_SYMBOL_POINTERS" }, // 0x06 + { "lazy_symbol_pointers", "S_LAZY_SYMBOL_POINTERS" }, // 0x07 + { "symbol_stubs", "S_SYMBOL_STUBS" }, // 0x08 + { "mod_init_funcs", "S_MOD_INIT_FUNC_POINTERS" }, // 0x09 + { "mod_term_funcs", "S_MOD_TERM_FUNC_POINTERS" }, // 0x0A + { "coalesced", "S_COALESCED" }, // 0x0B + { nullptr, /*FIXME??*/ "S_GB_ZEROFILL" }, // 0x0C + { "interposing", "S_INTERPOSING" }, // 0x0D + { "16byte_literals", "S_16BYTE_LITERALS" }, // 0x0E + { nullptr, /*FIXME??*/ "S_DTRACE_DOF" }, // 0x0F + { nullptr, /*FIXME??*/ "S_LAZY_DYLIB_SYMBOL_POINTERS" }, // 0x10 + { "thread_local_regular", "S_THREAD_LOCAL_REGULAR" }, // 0x11 + { "thread_local_zerofill", "S_THREAD_LOCAL_ZEROFILL" }, // 0x12 + { "thread_local_variables", "S_THREAD_LOCAL_VARIABLES" }, // 0x13 + { "thread_local_variable_pointers", + "S_THREAD_LOCAL_VARIABLE_POINTERS" }, // 0x14 + { "thread_local_init_function_pointers", + "S_THREAD_LOCAL_INIT_FUNCTION_POINTERS"}, // 0x15 +}; + + +/// SectionAttrDescriptors - This is an array of descriptors for section +/// attributes. Unlike the SectionTypeDescriptors, this is not directly indexed +/// by attribute, instead it is searched. +static const struct { + unsigned AttrFlag; + const char *AssemblerName, *EnumName; +} SectionAttrDescriptors[] = { +#define ENTRY(ASMNAME, ENUM) \ + { MachO::ENUM, ASMNAME, #ENUM }, +ENTRY("pure_instructions", S_ATTR_PURE_INSTRUCTIONS) +ENTRY("no_toc", S_ATTR_NO_TOC) +ENTRY("strip_static_syms", S_ATTR_STRIP_STATIC_SYMS) +ENTRY("no_dead_strip", S_ATTR_NO_DEAD_STRIP) +ENTRY("live_support", S_ATTR_LIVE_SUPPORT) +ENTRY("self_modifying_code", S_ATTR_SELF_MODIFYING_CODE) +ENTRY("debug", S_ATTR_DEBUG) +ENTRY(nullptr /*FIXME*/, S_ATTR_SOME_INSTRUCTIONS) +ENTRY(nullptr /*FIXME*/, S_ATTR_EXT_RELOC) +ENTRY(nullptr /*FIXME*/, S_ATTR_LOC_RELOC) +#undef ENTRY + { 0, "none", nullptr }, // used if section has no attributes but has a stub size +}; + +MCSectionMachO::MCSectionMachO(StringRef Segment, StringRef Section, + unsigned TAA, unsigned reserved2, SectionKind K, + MCSymbol *Begin) + : MCSection(SV_MachO, K, Begin), TypeAndAttributes(TAA), + Reserved2(reserved2) { + assert(Segment.size() <= 16 && Section.size() <= 16 && + "Segment or section string too long"); + for (unsigned i = 0; i != 16; ++i) { + if (i < Segment.size()) + SegmentName[i] = Segment[i]; + else + SegmentName[i] = 0; + + if (i < Section.size()) + SectionName[i] = Section[i]; + else + SectionName[i] = 0; + } +} + +void MCSectionMachO::PrintSwitchToSection(const MCAsmInfo &MAI, + raw_ostream &OS, + const MCExpr *Subsection) const { + OS << "\t.section\t" << getSegmentName() << ',' << getSectionName(); + + // Get the section type and attributes. + unsigned TAA = getTypeAndAttributes(); + if (TAA == 0) { + OS << '\n'; + return; + } + + MachO::SectionType SectionType = getType(); + assert(SectionType <= MachO::LAST_KNOWN_SECTION_TYPE && + "Invalid SectionType specified!"); + + if (SectionTypeDescriptors[SectionType].AssemblerName) { + OS << ','; + OS << SectionTypeDescriptors[SectionType].AssemblerName; + } else { + // If we have no name for the attribute, stop here. + OS << '\n'; + return; + } + + // If we don't have any attributes, we're done. + unsigned SectionAttrs = TAA & MachO::SECTION_ATTRIBUTES; + if (SectionAttrs == 0) { + // If we have a S_SYMBOL_STUBS size specified, print it along with 'none' as + // the attribute specifier. + if (Reserved2 != 0) + OS << ",none," << Reserved2; + OS << '\n'; + return; + } + + // Check each attribute to see if we have it. + char Separator = ','; + for (unsigned i = 0; + SectionAttrs != 0 && SectionAttrDescriptors[i].AttrFlag; + ++i) { + // Check to see if we have this attribute. + if ((SectionAttrDescriptors[i].AttrFlag & SectionAttrs) == 0) + continue; + + // Yep, clear it and print it. + SectionAttrs &= ~SectionAttrDescriptors[i].AttrFlag; + + OS << Separator; + if (SectionAttrDescriptors[i].AssemblerName) + OS << SectionAttrDescriptors[i].AssemblerName; + else + OS << "<<" << SectionAttrDescriptors[i].EnumName << ">>"; + Separator = '+'; + } + + assert(SectionAttrs == 0 && "Unknown section attributes!"); + + // If we have a S_SYMBOL_STUBS size specified, print it. + if (Reserved2 != 0) + OS << ',' << Reserved2; + OS << '\n'; +} + +bool MCSectionMachO::UseCodeAlign() const { + return hasAttribute(MachO::S_ATTR_PURE_INSTRUCTIONS); +} + +bool MCSectionMachO::isVirtualSection() const { + return (getType() == MachO::S_ZEROFILL || + getType() == MachO::S_GB_ZEROFILL || + getType() == MachO::S_THREAD_LOCAL_ZEROFILL); +} + +/// ParseSectionSpecifier - Parse the section specifier indicated by "Spec". +/// This is a string that can appear after a .section directive in a mach-o +/// flavored .s file. If successful, this fills in the specified Out +/// parameters and returns an empty string. When an invalid section +/// specifier is present, this returns a string indicating the problem. +std::string MCSectionMachO::ParseSectionSpecifier(StringRef Spec, // In. + StringRef &Segment, // Out. + StringRef &Section, // Out. + unsigned &TAA, // Out. + bool &TAAParsed, // Out. + unsigned &StubSize) { // Out. + TAAParsed = false; + + SmallVector<StringRef, 5> SplitSpec; + Spec.split(SplitSpec, ","); + // Remove leading and trailing whitespace. + auto GetEmptyOrTrim = [&SplitSpec](size_t Idx) -> StringRef { + return SplitSpec.size() > Idx ? SplitSpec[Idx].trim() : StringRef(); + }; + Segment = GetEmptyOrTrim(0); + Section = GetEmptyOrTrim(1); + StringRef SectionType = GetEmptyOrTrim(2); + StringRef Attrs = GetEmptyOrTrim(3); + StringRef StubSizeStr = GetEmptyOrTrim(4); + + // Verify that the segment is present and not too long. + if (Segment.empty() || Segment.size() > 16) + return "mach-o section specifier requires a segment whose length is " + "between 1 and 16 characters"; + + // Verify that the section is present and not too long. + if (Section.empty()) + return "mach-o section specifier requires a segment and section " + "separated by a comma"; + + if (Section.size() > 16) + return "mach-o section specifier requires a section whose length is " + "between 1 and 16 characters"; + + // If there is no comma after the section, we're done. + TAA = 0; + StubSize = 0; + if (SectionType.empty()) + return ""; + + // Figure out which section type it is. + auto TypeDescriptor = std::find_if( + std::begin(SectionTypeDescriptors), std::end(SectionTypeDescriptors), + [&](decltype(*SectionTypeDescriptors) &Descriptor) { + return Descriptor.AssemblerName && + SectionType == Descriptor.AssemblerName; + }); + + // If we didn't find the section type, reject it. + if (TypeDescriptor == std::end(SectionTypeDescriptors)) + return "mach-o section specifier uses an unknown section type"; + + // Remember the TypeID. + TAA = TypeDescriptor - std::begin(SectionTypeDescriptors); + TAAParsed = true; + + // If we have no comma after the section type, there are no attributes. + if (Attrs.empty()) { + // S_SYMBOL_STUBS always require a symbol stub size specifier. + if (TAA == MachO::S_SYMBOL_STUBS) + return "mach-o section specifier of type 'symbol_stubs' requires a size " + "specifier"; + return ""; + } + + // The attribute list is a '+' separated list of attributes. + SmallVector<StringRef, 1> SectionAttrs; + Attrs.split(SectionAttrs, "+", /*MaxSplit=*/-1, /*KeepEmpty=*/false); + + for (StringRef &SectionAttr : SectionAttrs) { + auto AttrDescriptorI = std::find_if( + std::begin(SectionAttrDescriptors), std::end(SectionAttrDescriptors), + [&](decltype(*SectionAttrDescriptors) &Descriptor) { + return Descriptor.AssemblerName && + SectionAttr.trim() == Descriptor.AssemblerName; + }); + if (AttrDescriptorI == std::end(SectionAttrDescriptors)) + return "mach-o section specifier has invalid attribute"; + + TAA |= AttrDescriptorI->AttrFlag; + } + + // Okay, we've parsed the section attributes, see if we have a stub size spec. + if (StubSizeStr.empty()) { + // S_SYMBOL_STUBS always require a symbol stub size specifier. + if (TAA == MachO::S_SYMBOL_STUBS) + return "mach-o section specifier of type 'symbol_stubs' requires a size " + "specifier"; + return ""; + } + + // If we have a stub size spec, we must have a sectiontype of S_SYMBOL_STUBS. + if ((TAA & MachO::SECTION_TYPE) != MachO::S_SYMBOL_STUBS) + return "mach-o section specifier cannot have a stub size specified because " + "it does not have type 'symbol_stubs'"; + + // Convert the stub size from a string to an integer. + if (StubSizeStr.getAsInteger(0, StubSize)) + return "mach-o section specifier has a malformed stub size"; + + return ""; +} |
